Automatic igniter for orchard-heaters



N. H. BRAY.

AUTOMATIC IGNITER FOR ORCHARD HEAIERS.

APPLICATION FILED MAR. 4, I919.

1,328,788, Patented Jan. 20,1920.

INVE N TOR BY 1/ 49mm fl wrroruwaw UNITED STATES PATENT OFFICE.

NELSON H. BRAY, OF SAN FRANCISCO, CALIFORNIA.

AUTOMATIC IGNITER FOR ORCHARD-HEATERS.

Specification of Letters Patent.

Patented Jan. 20, 1920.

Application filed March 4, 1918. Serial No. 220,150.

To all whom it may concern Be it known that I, NELSON H. BRAY, a.

citizen of the United States, and a resident of the city and county of San Francisco, State of California, have made a new and useful Invention-to wit, Automatic Igniters for Orchard-Heaters; and I do hereby declare the following to be a full, clear, 0011-,

by all of the orchard heaters within the danger zone will be simultaneously ignited, saving valuable time at a critical period.

This invention operates on the principle of utilizing a confined body of air which will contract with a drop in temperature, forming a partial vacuum which is utilized to siphon a quantity of acid into contact with an ignitible mixture adapted to propagate a flame, which will ignite the oil or other fuel within the orchard heaters.

In this specification and the annexed drawings the invention is illustrated in the form considered to be the best, but it is to be understood that the invention is not limited to such form because it may be embodied in other forms, and it is also to be understood that in and by the claims following the description it is desired to cover the invention in Whatever form it may be embodied.

In the accompanying one sheet of draw- 1n igure 1 is a diagrammatic illustration in elevation of an orchard heater having an igniter applied thereto in accordance with thls invention.

Fig. 2 is an enlarged elevation of an igniter constructed in accordance with this invention shown partially in cross section.

Fig. 3 is a cross section of the same, taken on the line IIIIII, Fig. 2.

In detail the construction illustrated in the drawings includes the acid chamber 1, preferably composed of a glass test tube, containing a quantity of sulfuric acid '2. The open end of the tube is closed by the sto per 3 preferably of rubber, provided wit a groove as at 4 to form a vent admitting atmospheric pressure to the acid tube 1. The air chamber 5 is preferably a glass test tube, similar to the tube 1 but of greater ca pacity, inverted and forced over the extension 6 of the stopper or plug 3. This plug has a central longitudinal opening to receive the glass tube 7, having its lower end immersed in the acid 2 and extending through the plug, above the level of which it terminates within the chamber 5. The plug hermetically engages the outer surface of the tube 7 and the opening of the tube 5, whereby the chamber within the tube 5 is hermetically sealed from the atmosphere, except through the acid chamber 1. Within the chamber 5 resting upon the plug 6 adjacent to the upper end of the tube 7 is an annular tablet 8 composed of-a material adapted to be ignited by sulfuric or other acid. For

this purpose I prefer to use What is commercially known. as Greek fire, composed of chlorate of potash and brown sugar, with various modifications.

The cover X of the heater is provided with an opening to receive the ignition device, leaving a portion of the chamber 5 exposed. For this purpose I provide the chamber 5 with a flange or ring 9 preferably of rubber, to engage the edges of the hole in the cover X, to suspend the device with the combustible element within the heater.

The invention operates substantially as follows: The orchard heaters are distributed through the orchard or other area to be protected in the usual manner, and are preferably filled with crude oil or other fuel, such as X The cover X is placed in position and the ignition device inserted within the cover, preferably suspended above the fuel.

A drop in temperature brings about a proportionate contraction of the volume of air within the chamber 5, until a partial vacuum is formed therein at the dangerous temperature, say 40 Fahrenheit, at which time this partial vacuum will exert its suction through the tube 7 drawing the acid 2 therethrou 'h and discharging it onto the combustible ta let 8, which is ignited thereby, giving off a large volume of combustible gases, the heat and pressure of which will explode the glass tube 5, at which time the liberated combustible gases will burst into flames igniting the fuel X within the heater. The ignition of the fuel within the heater causes a large volume of heat to be given off through the stack X warming the zone threatened with frost, in the usual manner.

By the use of this invention, only those orchard heaters which are within the immediately threatened zone of frost will be ignited, which accomplishes a great saving in fuel in large orchards where only a restricted area might be threatened. The other heaters will not be ignited until the dangerous dro in temperature spreads thereto. A sti l greater advantage is that all of the orchard heaters within the threatened area' will be simultaneously ignited by this automatic means. Because of the great expense of operating orchard heaters, they are not ignited until the danger point is reached, which may be a matter of only a few degrees, and because of the labor incidental to igniting these heaters by torches or other means now in practice, it is impossible, without more help than isusually available, to ignite a. sufficient number of heaters within the zone to raise the temperature above the frost point.

The tablet form of ignitible powder as at 8 is preferred for the reason that powdered or granulated substances would be liable to ignition by sifting into the acid through the tube 7, particularly in assembling the device for use. As the acid 2 passes out of the tube 1, air pressure through the vent 4: prevents the formation of a vacuum between the end of plug 3 and the surface of the acid. In handling the device before it is inserted in the heater, the tube 1 is forced up. onto the plug 3 to close the top of the vent 4 and prevent the spilling out of any of the acid 2. Just before inserting into the cover X the tube is partially withdrawn from the plug 3to open the top of this vent 4. In the sealed condition it is impossible for any of the acid 2 to reach the chamber 5, should the device be dropped or laid on its side, as the quantity of acid is proportioned to the size of the tube 1 so that the lower end of the tube 7 will be exposed if the device was inverted or laid on its side. Only a small quantity of acid is necessary for the purpose, the quantity of acid in proportion to the volume of air, is the determining factor in regulating the degree of heat at which the two elements will be mingled.

Having thus described my invention, what I claim and desire to secure by Letters Patcut is:

1. An igniter including areservoir adapted to contain liquid; a sealed chamber adapted to contain an ignitible compound; and a tube submerged. in said liquid and extending into said chamber adjacent to .said compound.

2. An igniter including a reservoir containing liquid; a sealed chamber containing a compound ignitible by said liquid; a tube having one end sealed by said liquid and extending into said reservoir, whereby said liquid will be drawn into said chamber by volumetric contraction of the contents of said chamber.

3. In combination with an orchard heater, an igniter including a reservoir adaptedto contain liquid; a sealed chamber adapted to contain 'acompound ignitible by said liquid; a passage between said reservoir and said chamber; whereby said liquid will be drawn into said chamber by volumetric contraction of the contents of said chamber.

An igniter including separate containers. each to contain substances adapted to be co-mingled to produce combustion, and a connection between said containers through the-medium of which said substances are mingled by the volumetric action of a content in one of said containers, said action being caused by variations in atmospheric temperature.

5. An igniter comprising a breakable container and a reservoir, each containing substances adapted to be co-mingled to produce combustion, and a thermally controlled pas sage between the container and reservoir through which the contents of the latter will be drawn into the container by volumetric contraction of the contents in the container to mingle said substances, whereupon the container is broken by the expansion and combustion of the co-mingled substances.

6. In combination with an orchard heater an igniter insertible in a wall of the heater, said igniter including a breakable container having a flange intermediate its ends for supporting the igniter in the heater, a reservoir, said container and reservoir being adapted to contain substances to be comingled to produce combustion, and a thermally controlled passage between the container and reservoir through which the contents of the latter will be drawn into the container by volumetric contraction of the contents in the container to mingle said substances, whereupon the container is broken by the expansion and combustion of the comingled substances.

In testimony whereof, I have hereunto set my hand at San Francisco, California, this 25th day of Feby 1918.

NELSON H. BRAY.

In presence of LINCOLN V. JoHNsoN, A. J. HENRY. 

